Kind of like back when they might have, you know, signed up for that machine learning course with all that tricky linear algebra and stuff (which they never really learned the first time around -- perhaps because they were figuring that, like Peter Thiel, they were probably just going to drop out anyway).
Except this time around the consequences aren't about having some professor get grumpy at them, or wasting their tuition fees. It's about people -- who once considered them as friends, and trusted them implicitly -- being laid off, missing mortgage payments, having romantic partners leave them... fun stuff like that.
So "anxiety", "depression" are nice ways of saying that they've bitten off more than they can chew, and are basically shitting their pants... and praying for some higher power (an investor, an advisor, or a customer) to bail them out. Except it's not gonna happen. There's nothing going to stop their car from hitting that brick wall at 50 miles an hour this time, without a seatbelt.
So what's happening isn't that they're succumbing to mental illness... it's that they're learning, through their bodies and their minds, the way the world really works, and what impact their actions (and naïveté) can sometimes have, in terms of real consequences.
In, you know, that big scary world out there.